Absent climate change, a good 15,000-year forecast

LONDON - Weather for about the next 15,000 years should be warm and stable -- barring human interference -- according to scientists.

They have drilled three km (1.8 miles) into the Antarctic ice to produce the oldest-ever continuous climate record, from an ice core dating back 740,000 years.

It shows eight ice ages, or glacials, followed by shorter interglacial periods and changing concentrations of gases and particles in the atmosphere.

The period that corresponds most to the present interglacial period, which started 12,000 years ago, was about 400,000 years ago and lasted roughly 28,000 years.

"Our data say we won't go into another ice age. We have 15,000 years before that is coming," Dr. Eric Wolff, of the British Antarctic Survey, told a news conference on Wednesday.

But concentrations of greenhouse gases such as methane and carbon dioxide (CO2) today are the highest seen in the last 440,000 years. "We have no experience of (this) in the past," said Wolff.

The scientists now plan to extract air from tiny bubbles in the ice to determine how the atmosphere's composition has varied. By studying past climate patterns and comparing them with present conditions, the researchers hope to get a better idea of future trends and how atmospheric conditions will influence them.

Scientists from 12 centres in 10 European countries have worked on the eight-year EPICA (European Project for Ice Coring in Antarctica) project. Their first results are published in the science journal Nature.

They plan to drill 100 metres (328 ft) further into the ice in one of the most hostile places on the planet to reach ice that is 900,000 to one million years old.

Drilling is limited to just two months of the year, December and January, because the average annual temperatures are below -54 degrees Celsius (-65.20F). Blizzards are common and the scientists travel thousands of kilometres by tractor to work on the project.

"Antarctica has now yielded the longest ice-core record yet, one that covers a staggering 740,000 years with more to come," Jerry McManus, of the Woods Hole Oceanographic Institution in Massachusetts, said in a commentary.